A variety of applications require the ability to rapidly fill a container with a fluid. To accomplish this rapid filling, the fluid is typically pumped (under pressure) into the container. Due to this rapid filling, such applications typically include means for quickly shutting off the flow of fluid when the container reaches a predetermined level of fluid held therein so as to prevent overfilling and/or spillage of the fluid. Such applications typically include a fluid level sensor for sensing the level of the fluid.
One type of a fluid level sensor is a “jet level sensor.” Jet level sensors technology has been available for decades, and is primarily used today to control bottom loading valves on large fuel tanker trucks. A jet level sensor operates without any moving parts. Because of that, a jet level sensor can (theoretically) work indefinitely without needing worn parts to be replaced or maintained. Jet level sensors can be horizontally or vertically oriented within the container.
Horizontal jet level sensors. Many traditional jet level designs have been established around a horizontal jet stream installation. This enables the fluid level in the tank to reach a single critical point on the body of the jet level where the jet becomes submerged and reaches a cross port on the outlet side of the jet causing the fluid stream to attach to an adjacent curved surface all at a simultaneous time. The occurrence of these happening at a time ensures that the fluid stream is diverted from the receiving point and stays diverted across a wide range of pressures (1-150 psi).
When a traditional horizontal jet level is oriented vertically, this causes these functional features to occur at different times (fluid levels) which impacts the sensors ability to shut off at a single point and remain “off” across a wide range of pressures. When the jet level is vertically oriented in the container, as the container is filled, the jet receiver is submerged first, followed by a cross port (if present), and finally the jet nozzle. At low pressures, when the jet receiver becomes submerged, there is enough turbulence to cause the jet stream to be disrupted and an associated pilot valve will close. However, at high pressures, there may not be enough turbulence to cause the jet stream to be clearly disrupted. When this happens, a “hammering” effect may result where the valve repeatedly opens and closes as the system goes from high to low pressure until such time it reaches the cross port and begins introducing enough fluid through the cross port to cause clear disruption of the jet stream. Because of this issue, prior art jet level sensors tend to not work well across a range of pressures, and regularly, in such a high pressure environment, fail to shut off at a single predetermined level, as desired. Additionally, this cycling on and off occurs at relatively high pressures and can cause damage to pumps and infrastructure.
Another common issue in such systems (which have a cross port), is the occurrence of air bubbles as a result from the fluid spray. These air bubbles can interfere with the “priming” of the cross port, decreasing the cross port's ability to timely disrupt the jet stream.